This Program involves several projects related to the molecular biology of viral tumorigenesis and related mechanisms of genetic regulation: 1) Enzymatic mechanisms of replication of adenovirus DNA by soluble nuclear extracts of infected cells; 2) Regulation of synthesis of "acute phase" liver proteins of mice; 3) Mutational analysis of the SV40 replicon; 4) Specific nuleic acid interactions of restriction and modification enzymes; and 5) Enzymatic mechanisms of repair of DNA damage in bacteria.